The investigators supporting this application have inadequate access to high quality laser scanning confocal microscopy resources. Improved access to such equipment is important to the advancement of their ongoing NIH- funded research programs. For this reason they have joined together in this application requesting funding for the purchase of a state of the art laser scanning confocal microscope. The major users of this shared microscope require access to a high quality confocal microscope for a variety of reasons. Many of the users need to image small structures in the nuclear interior using nucleic acid and antibody probes which are fluorescently tagged. The second group of investigators needed to localized fluorescently tagged molecules in tissue sections and embryos. Laser scanning confocal microscopy meet the research needs of these investigators far better than any existing technology. The investigators joining together in this application are requesting funding for a Leica TCS NT microscope with some supporting equipment. We believe this to be the best available instrument for our research needs. The microscope will be administered as a shared resource in space provided the Department of Cell Biology, the department in which most the major users have primary or secondary appointments. Recurring costs will be covered by a user fee, with some help from the Department of Cell Biology in the first year.